The door at the base of the nearer tower gives some idea of scale, but I think the tower itself is ~60 m tall, supporting a rotor with a diameter of 80 m. The nominal output* of each Vestas turbine is 2 MW, so the eight units can, in theory, supply 8,946 'average' homes, or 1-in-20 houses in Lancaster. That compares rather favourably to the original ten Windmaster turbines installed in 1994, which had a collective output of only 3 MW.

Incidentally, the repowering project has been falsely cited by anti-windpower campaigners as 'evidence' that turbines have a very short lifespan. In the eleven years the ten Windmasters were operating, there were only two gearbox failures (admittedly that's according to the operating company) and the turbines were functional until the day they were replaced. They were obsolete, but not 'broken'.
Caton Moor was one of the first commercial wind farms in the UK, using immature technology which, frankly, perhaps wasn't the best for the situation. Eleven years of practical experience (both specifically on-site and generally within the industry worldwide) informed what seems to have been a better choice; there's no reason to think the Vestas turbines will be removed so soon.
I'm no Green, and certainly don't support windpower generation blindly, but bogus claims (by either side) need to be refuted.

*: Nominal and actual outputs differ slightly: according to Vestas' own published specifications, optimal output is at a wind speed of 15 m/s and generation has to shut down in winds above 25 m/s. I happen to know (this was part of my PhD research catchment, remember?) the average recorded wind speed on Caton Moor between 1994 and 2000 was 8.38 m/s. However, the physics means average wind speed is of limited relevance (a tiny change in speed can have a huge impact on generation) and though not a panacæa, the wind farm is still a very worthwhile supplement to Heysham's nuclear reactors.